1. Field of the Invention
The present invention relates to a fuel cell, a fuel cell stack and a method of manufacturing the same, which are suitable for constructing a separator with a metal plate. In particular, the present invention is directed to a fuel cell stack and a method of manufacturing the same for a fuel cell mounted in a vehicle.
2. Description of Related Art
A solid polymer type fuel cell includes a solid polymer electrolyte membrane having proton conductivity. Such a fuel cell is configured to supply a fuel gas to an anode of a pair of electrodes, wherein the electrolyte membrane is interposed between such electrodes. The fuel cell is also configured to supply an oxidizer gas to a cathode and generates an electric power using an electrochemical reaction occurring on a surface of the electrolyte membrane.
A single cell includes an electrolyte membrane electrode assembly (MEA) formed by interposing the electrolyte membrane between a pair of electrode catalytic layers. The cell further includes a separator for defining a gas flow passage at both sides of the electrolyte membrane electrode assembly.
The separator defines a gas flow passage for distributing a fuel gas or an oxidizer gas. It also defines a temperature control medium flow passage for distributing a temperature control medium.
Further, the separator is made from a conductive material in order to serve as a conductive path and for extracting an output from the electrode catalytic layers of each cell.
In a related device, a carbon separator having both corrosion resistance and conductivity is generally used for a fuel cell. However, in another related device, a metallic separator has been provided in order to reduce the cost of the product while improving the power density by thinning the separator.
Japanese Laid-Open Patent Publication No. 2004-127699 includes an example of a fuel cell with a metallic separator, which is configured as two separators welded together to defines a gas manifold that passes through the cell.